Liquid hydrogen is a fuel that could be used to generate power on a small scale. The most likely future application of this is in hydrogen vehicles. Hydrogen-powered vehicles are equipped with a fuel cell that is filled with hydrogen. The fuel cell helps keep the liquid hydrogen stable while it is being used.
However, one of the problems of hydrogen is that it is a secondary energy source. Hydrogen has to be manufactured before it can be useful as a fuel. Manufacturing hydrogen requires energy and due to the law of conservation of energy you cannot get more energy out of something then you put into it. In other words, it takes more energy to create hydrogen for fuel than the amount of energy we get out of it as a fuel.
The other challenge with hydrogen is infrastructure. At most temperatures on earth, hydrogen wants to be in a gaseous state. Storing it means that the containers must be perfectly sealed and capable of withstanding high pressures. Since hydrogen is the smallest atom, even the tiniest leak in the tank or pipes will allow hydrogen to escape. This is a challenging problem to fix.